Short answer
In Arizona, change the sediment, carbon and polishing filters every 6 to 12 months, and the RO membrane every 2 to 3 years. Once a year is the easiest schedule to remember.
What each filter does
- Sediment filter: catches dirt, sand and rust
- Carbon filter: removes chlorine, which protects the membrane and improves taste
- RO membrane: removes PFAS, arsenic, lead and dissolved solids
- Polishing filter: a final taste and smell clean-up
Replacement schedule
- Sediment and carbon filters: every 6–12 months
- Polishing filter: every 6–12 months
- Alkaline filter, if you have one: every 6–12 months
- RO membrane: every 2–3 years
Arizona’s hard water and chlorine wear filters faster than in many places, so lean toward the shorter end.
Signs your filters are overdue
- The RO faucet runs slowly or the tank takes longer to fill
- The water tastes or smells off
- The water looks cloudy
- The system makes new noises
What if I skip it?
Old filters clog, stop protecting the membrane and can grow bacteria. You also lose the protection you bought the system for.
Let us handle it
We do yearly filter changes on any reverse osmosis system, including adding an alkaline stage. Call (602) 730-0262.
Common questions
How do I know when to change my RO membrane?
Usually every 2 to 3 years. A slow faucet or a change in taste after you’ve already changed the filters is a sign the membrane is due.
What does an alkaline filter do?
It adds calcium, magnesium and potassium back after reverse osmosis, which raises the pH and gives the water a crisp taste.